Continuous annealing furnace



M. VAN MA'RLE. CONTINUOUS ANNEALING FURNACE.

APPLICATION FILED MAR. 1511-922.

Patented Sept. 19, 1922..

2 SHEETS-SHEET 1L Q s Qw. W

M. VAN MARLE.

CONTINUOUS ANNEALIUNG. FURNACE.

APPLICATION FILED MAR. 1.5. 1922.

2 SHEEYT\SSHEET 2.'

Patented Sept. 19, 1922;

Patented Sept. 19, E922.

CONTINUOUS ANNEALING FURNACE.

Application filed March 15, 1922. Serial No. 543,918.

T 0 all whom it may concern:

Be it known that I, MARTIN V-AN MARLE, a subject of the King of GreatBritain, residing at Dibdale lVorks, Dudley, in the county of orcester,England, have invented certain new and useful Improvements in andConnected with Continuous Annealin Furnaces; and I do hereby declare thefo lowing to be a full, clear, and exact description of the same.

This invention has reference to continuous annealing furnaces of thekind in which there is a retort or other heating chamber provided withwater sealed ends through which the goods are passed by an endlessconveyor. This heatingchamber contains steam or an inert gas so that thegoods are prevented from oxidizing in any way in their passage throughthe same, but they leave the water seal on the outlet end perfectlybright and free from' scale. .The heating chamber is usually arranged tobe heated by the combustion of producer gas and heated air in a chambercommunicatin with transverse fiues around the outside 0 the heatingchamber.

Heretofore in this kind of continuous annealing furnace, the endlessconveyor is usually composed of several flat link chains fixed togetherside by side and spaced apart by cross bars at the joints and togetherforming a conveyor of the required width.

on WhlCll the goods are carried. These chains ass slowly over sprocketwheels beyond t e inlet and outlet tanks. are suitably guided and returnunderneath the heating chamber. They are adapted to pass down into awater tank at the inlet end and carry the goods up and out of the tankinto and through the hood and inlet mouth into and along the heatingchamber. The goods are conveyed out of the heatingchainber.

at the outlet mouthand down through the open bottom of the hood into thecooling water tank from which the goods are removed by an attendant.From this point theconveyor chains rise and pass over the sprocketwheels to return underneath the furnace as aforesaid.

Hertofore it has been customary for the sprocket wheels which are fixedside by side on a driven shaft at the forward end to pull the chains andgoods through the heatin chamber. The chains are held down in the tanksor in the cooling tank by means of edge rollers fixed on" pinsprojecting from the sides of the cooling tank and under which theconveyor chains pass, spaces being left between the rollers to clear thegoods on the chains. It is found in practice that the chains in courseof a short time. stretch and have to be shortened and ultimately becomestretched to such an extent that they will no longer gear with thesprocket wheels and then they have to be discarded for new chains. i

The object of the present invention is to overcome the defect and toprovide an improved and'simplified arrangement which will reduce thetensile strain on the endless conveyor chains and enable them to lastwith a minimum of stretch for a considerablylonger time than at present.

According to this invention, the, furnace is provided with a conveyorwhich hangs in one or Imore loops and which is positively driven at thesame speed at both ends to maintain the loops and thereby carry thegoods through the quenching fluid on its way to and from. the heatingchamber.

It has been proposed to drive the conveyor chains of a tempering machineat the same speed at both ends but in this case the conveyor was flatfrom one end to the other.

Referring to the drawings F igure 1 is asectional elevation of a furnaceaccording to this invention.

Figure 2 is a plan view thereof.

Figure 3 is a detail elevation of means to control the speed of travelof the conveyor chain showing the same in one position.

Figure 4 is a similar View of the control means at the opposite end ofthe furnace.

In the'construction illustrated upon the accompanying drawings, thefurnace ineludes the usual tank 1' adapted to hold the inlet end toreceivethe goods and carry them into and through the heating chamber,'and atthe outlet end to deliver the goods from the heating chamber intothe cooling tank.

The usual edge rollers-to keep the chains down in the tank are now notrequired and are dispensed with. Thus, as all these four sets ofsprocket wheels are positively driven, and each set has only'to drive ashort section of the complete conveyor, it follows that the tensilestrains, on the conveyor chains are very considerably reduced.

Moreover, by sectionally driving and supporting the conveyor chains byseveral sets of sprocket wheels as aforesaid so that the stretch andwear on the conveyor chains is so-considerably reduced, it is possibleto very materially increase the Width of the heating chamber andcombined conveyor chains and moreover, the cross rods which havepreviously been employed for tying the various chains together tomaintain them at the proper distances apart sideby side -can bedispensed with, as any lateral spread of the conveyor chains where theyrun throu hthe tanks and heating chamber is effectua ly prevented by theadditional sets of sprocket Wheels which are provided as aforesaid inthe water tanks under the inlet and outlet hoods.

It is to be understood that the peripheral speed of all the sprocketwheels is the same.

The two horizontal shafts 12 on which are mounted the two sets ofsprocket wheels in the water tanks as aforesaid are each supported bybearings 13 fixed to the sides of the tank. One of the said bearings foreach shaft is made as a stufiing box 14 through which the said shaftprojects for driving,

' and this shaft has an external sprocket wheel 15 which gears with anendless chain 16 from a corresponding sprocket wheel 17 fixed on theadjacent sprocket wheel shaft 18 beyond the tank. The two end sprocketwheel shafts outside the tank are simultaneously driven preferably froma first motion shaft 19 near one of the end tanks. This shaft ispreferably fitted with a coned pulley 20.and driven from a similar conedpule ley on a driving shaft, not shown, so as to run the conveyor cha1nat varlous speeds.

wheel shaft 18 is driven from this counter shaft by another pinion 31gearing into a spur wheel 32 on the sprocket wheel shaft so that by thismechanism a slow intermittent rotary motion is transmitted from thefirst 6t} motion shaft to the end sprocket wheel shaft messed 18, andalso to the shaft'12 in the water tanls by means of the sprocket wheel17, endless chain 16, and sprocket wheel 15. A similar ratchet wheelshaft gears on to a counter shaft which is geared to the sprocket wheelshaft provided at the extremei end of the outlet tank, and the ratchet l'ver on this ratchet wheel shaft is driven from the ratchct lever on thefirst said shaft by means of an arrangement of links and connectingrods. One of these 35 pxtends from the first ratchet lever to apivotedlever 34: mounted above the furnace which by a horizontalconnecting rod 36 is connected to another pivoted lever 34 at the otherend of the furnace and this by an inclined connecting rod 35* isconnected to the other ratchet lever.

In order to obtain a variation in the travelling speed of the conveyorchains, it is preferred to employ on each of the ratchet wheel shafts anarrangement ofthree ratchet wheels 2626 --26 close together made withtheir teethof different pitches so that the pawls can be moved to gearwith either of' the ratchet wheels according to} the speed of travel ofthe conveyor chain re uired.

@Tn order to prevent any possibility of the set of sprocket-wheels atthe inlet end over running the sprocket wheels at the outlet end whichmight be caused through the pawl at the outlet end from some causefailing to engage the ratchet wheel and turn the ratchet wheel shaft, itis preferred for there to be end any suitable free wheel such as thatshown in Figure 4 and indicated by the.

' introduced in the driving gear at'theoutlet the outside links, eachtooth being preferably formed with a flat plate portion forming a sectorof a circle of the same diameten as the intermediate disc to which theseplates are bolted or otherwisesecured so that they can readily beremoved and replaced when worn or broken. v

6 In combination with the end sprocket wheels, suitable guide rollers44: are provided to maintain the advancing .chain in the best sition forthe sprocket teeth to engage with it and also to cause the chainstoproperly disengage the sprocket teeth as. they leave them. Between theinlet mouth" of the heating chamber and the sprocket wheel's adjacentthereto, it is preferred to provide a narrow clearing plate 45 whichjust clears its,

the sprocket teeth on the sprocket wheels and causes the properdisengagement of the chains from the sprocket teeth and prevents thechains from being carried down out of the horizontal with the sprocketteeth.

Instead of the pawl and ratchet wheel intermittent driving gear abovedescribed for driving the sets of the sprocket wheels simultaneously,any other suitable arrangement of driving gear may be employed for thispurpose, such driving gear being either intermittent or continuous.

Moreover, my invention comprises improvements in the construction of thehoods which are fitted on the mouth pieces of the heating chamber anddip into the water in the tanks to form the seals. Each of these hoods Ipreferably form of an end frame 50 which has an opening 51 correspondingwith the opening in the flanged mouth piece of the heating chamber towhich this frame and flanged side plates are bolted or otherwise fixedand covering the top and inclined front of the hood there ars steel orother plates 52 which are bolted or otherwise fixed to the two cast ironside plates. Thus there is formed a comparatively inexpensive and easilymade hood having enclosed sides and top and front with an open bottomand open end to the heating chamber.

The said cast iron side plates of the hood are preferably provided withman holes furnished with suitable covers, or have easily detachablewindows immediately over the said sprocket wheels so that they can beinspected, and so as to facilitate the release of any goods on theconveyor chain which may have fouled the hood.

\Vhat I claim then is I l. A continuous annealing furnace comprising aheating chamber, liquid seals for both ends of said heating chamber, anendless conveyor for the goods passing through said heating chamber andin slack loops through said water seals, and means for positivelydriving said conveyor at the same speed at both ends of the furnace,whereby the conveyor loops in the water seals are maintained.

2. A continuous annealing furnace com-- prising a heating chamber,liquid seals for both ends of said heating chamber, an endless conveyorfor the goods passing through said heating chamber and in slack loops;through said water seals and inter-connected driving gear for positivelydriving said conveyor at the same speed at both ends of the furnacewhereby the conveyor loops in the water seals are maintained.

3. A continuous annealing furnace comprising a heating chamber, a liquidseal for the ends of said heating chamber, an endless conveyor for thegoods passing through said water seal and heating chamber, and means forpositively driving said conveyor at the same speed at both ends of thefurnace whereby the conveyor can han in loops in the water seal at eachend of t 1e heating chamber and thus carry the goods through the liquidon its way to and from the heating chamber, and a free wheel device topermit the driving gear to be run independently of the drive.

4. A continuous annealing furnace comprising a heating chamber, a liquidseal for the ends of said heating chamber, an endless conveyor for thegoods passing through said water seal and heating chamber,inter-connected driving gear for positively driving said conveyor at thesame speed at both ends of the furnace whereby the conveyor can hang inloops in the water seal at each end of the heating chamber and thuscarry the goods through the liquid on its way to and from the heatingchamber, a driving shaft for actuating said driving gear, and a freewheel device to permit the driving gear to be run independently of thedrive.

5. A continuous annealing furnace comprising a heating chamber, liquidseals for both ends of said heating chamber, an endless conveyor for thegoods passing through said heating chamber and in slack loops throughsaid water seals, sprocket wheels for positively driving said conveyorat each end, and means for driving said sprocket wheels at the samespeed at both ends of the fur nace, whereby the conveyor loops inthewater seals are maintained.

6. A continuous annealing furnace comprising a heating chamber,seals-for both ends of said heating chamber, an endless conveyor for thegoods passing through said heating chamber and in slack loops throughsaid water seals, discs mounted for rotation at spaced intervals alongthe length of the furn-ace,; and adapted to support said conveyor, andmeans for positively driving all of he discs at the same speed, wherebythe convy0r loops in the water seals are maintained.

In witness whereof I afiix my signature. MAR-TIN VAN MARLE.

